Patients who are admitted with rest angina are treated with a short 5-day treatment with Azithromycin. Azithromycin is an antibiotic, FDA approved and widely used for the treatment of the respiratory infections with Chlamydia pneunomiae. All other medications and treatment for the patients will be deemed necessary by the admitting physician. These patients are followed for six months and determined whether the treatment with Azithromycin prevents new coronary events.